Perhaps you should try some spelling variations:
hermann ebook » german book
heimann book » german book
heilman book » german book
a robert » 3 robert, dr robert, a robot
robert e » robert j
a robust » _ robust
robust e » robust _, robust a, robust end

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (((( a robert e. heimann book ) or ( a robert _. hermann ebook ))) or ( a robust e. heilman book ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((( a robert e. heimann book ) OR ( a robert _. hermann ebook ))) OR ( a robust e. heilman book )).
• Adding a wildcard symbol may retrieve word variants: (((( a robert e. heimann book ) or ( a robert _. hermann ebook ))) or ( a robust e. heilman book ))*.